Synthesis of flexible and porous cobalt hydroxide/conductive cotton textile sheet and its application in electrochemical capacitors

► Porous conductive cotton sheets result in good conductive interconnecting network. ► Co(OH)2 dispersed on the conductive cotton sheets under hydrothermal condition. ► Flexible, lightweight, cheap and porous composites for supercapacitors. ► A large-scale approach to produce flexible, lightweight, and porous electrodes. In the work, multi-walled carbon nanotubes (MWCNTs) were coated uniformly onto the cotton fibers to make porous conductive cotton textile, where MWCNTs formed an electrically conductive interconnecting network. Then, a flexible, lightweight, cheap and porous composite was synthesized for electrochemical capacitors (ECs) by dispersed pseudocapacitive cobalt hydroxide well onto the conductive cotton textile sheet. Electrochemical results show that the unique flexible and porous composite owns the ability to deliver large area specific capacitance of 11.22 F cm −2 and good electrochemical stability of 4% capacity loss after 2000 cycles at high rates. Moreover, the extremely simple design and fabrication process we proposed here provide a universal and efficient approach to large-scale production of flexible, lightweight, low-cost and porous electrode for ECs application.